This application seeks support for a new Small Animal Imaging Resource (SAIR) at Vanderbilt University, dedicated to providing scientific and technical resources and support for non-invasive imaging of small animal models of cancer in vivo. The equipment and personnel needed to support cancer imaging in small animals will be provided by a new center which provides access to a comprehensive array of imaging resources. The center currently allows state-of-the-art studies of small animals in vivo using high field MRI, X-ray CT, optical, ultrasound and nuclear imaging techniques including microPET and microSPECT. This new imaging center is currently housed in 4000 sq ft of space that has been completely renovated to house state-of-the-art instruments. The facility is supported by an expert faculty dedicated to developing new and improved imaging methods and their applications, contiguous laboratory spaces for animal preparation and monitoring, computing resources for image analysis and processing, and an electronics workshop for developing instrumentation and other technical support. The SAIR would further develop this infrastructure for cancer imaging, and would also advance and integrate new imaging technologies for the comprehensive evaluation and characterization of small animal models of cancer. Specific technological developments would be undertaken in MRI and microSPECT imaging. The SAIR would emphasize combining and integrating the information from different modalities to evaluate specific biological and molecular processes in mouse models. It would develop new imaging instruments and techniques, agents and algorithms to acquire and combine the information obtainable from high field (9.4T, 7T and 4.7T) MRI, novel optical imaging methods, microPET and microSPECT imaging, X-ray CT, ultrasound, imaging mass spectrometry (MALDI), and histology. It would support the development and application of new computer data analyses and image processing methods to combine and correlate these data sets, as well as the provision of a core resource for developing novel targeted contrast agents for each modality. These capabilities would be applied to several funded research projects, many of which are already using imaging extensively, including studies of specific molecular pathways and mechanisms in transgenic or xenograft mouse models of prostate, hepatocellular, pancreatic, breast, colorectal and skin cancers. The SAIR would be invaluable for supporting ongoing research in tumor biology and molecular imaging within a leading cancer center, and for training of cancer scientists in the applications of imaging methods.